Cutter-chain block



April 18, 1933. N K BOWMAN 1,903,771

CUTTER CHAIN BLOCK Filed June 10, 1932 v Patented Apr. 18, 1933 UNITED STATES nnwron K. 30, or nownn, omo

Applitatfion filed dune 10,

that they form a continuous endless chain cated at 3 in dotted'line's,: to

which is driven around a supporting cutter bar so that hits mount ed upon the bit blocks will be caused to engage and form clefts in a bank of coal to facilitate subsequent breaking down of the shelf of coal. Removable and reversible bits have been heretofore provided and have been held between two clamping members which; are secured to the bit block and a securing screw has been provided to aid the bit-holding members 1n resisting the thrust to which the'bits have been subjected in action, but it has been found that with the screw dis osed substantially at a right angle to the bit the thrust was received upon the end of the screw and the screw tended to work loose and failed tomaintain a lasting eng ement with the parts which were seccording to the present invention, the securing bolt or screw is so disposed and the cooperating parts are so formed that friction will be utilized to resist the thrust and the strain u on the bolt will, consequently, be lessened. The invention is illustrated the accompanying drawing in which Figure 1 is a view, partly in section and partly in side e1e-. vation, of a bit block and a bit secured there-. on according to the present invention.

Fig. 2 is a to plan view of the same.

The bit bloc 1 is constructed with openings 2 adjacent its ends whereby it may be pivotally attached to couplin links, indie fitted in a chain, and each bit block is provided, at its inner side, with a tooth i ada ted to engage sockets in a drivin wheel an guide grooves in a cutter bar w ereby the chain will be guided and supported. At its oute'r'side or edge, the bit block is formed with an exten- $1011 or abutment 5 having a reces in one side adapted to receive a holding member 6- having an enlarged foot 7 engaging in a re cess 8 in the block which recess extends into the face of the abutment extension 5 so that tion, seating within the mem amen use. Serial No. 616,535.

the bit-receiving wedge or holder 6 will be retained in the bit, block against outward thrust. The inner face of the abutment 6 is provided with a groove 9 suitably shaped to provide a seat for the reversible removable bit 10, the end of the bit projecting beyond the seat, as clearly shown in Fig. 1, so that it may. properly engage and cut into thebank of coal. Between the abutment 5 and the opposite end of the bit block, the outer edge or face of theblock is straight toprovide a support for the tapered clamping block or wedge 11 which has its endmember suitably shaped to provide a seat for the lower end or corner of the bit, as clearly shown in Fig. 1. The longer side of the clamping block or wedge 11 seats against the outer edge or face of the bit block while the outer side of the wedge converges toward the block from the bit. A11 obliquely disposed opening 12 is formed through the clamping block 11 and a; threaded socket or bore 13 is formed in the bod of the bit block and alined axially with sai opening, the diameter of the opening be ing greater than the opening of the threaded bore or socket. in order to permit some adjustment of the clamping block. A securing bolt 14 is inserted through the opening 12 and has its threaded shank engaged in the threaded socket or bore 13, as clearly shown in Fig. 1, a washer 15 being placed over the outer end of the opening or hole 12 under the head ofthe bolt so as to provide a firm bearing for the bolt head, as will be understood. In assembling the parts, the bit seat or holder 6 is first engaged in the bit block so that the heel of its foot 7 will engage in the notch provided therefor in the abutment member 5. The bit is then laced in posier 6, and the clamping block-11 is-then brought into en- 'gagement with the bit, whereupon the clamping bolt 14 is turned home so as to firmly hold the parts together. 1 9

It will be understood that, in use, the cutter chain is moved in such direction that the of the bit to move away from the seat or holdin member 6 and this tendency is resisted y the clamping block 11. In the present arrangement, the block is secured in such a manner that there is a very high degree of friction between the opposed surfaces 0 the clamping block and the bit block which resists the tendency of the bit to rock in the stated manner so that the bit will be very firmly held to its work. The thrust is: only indirectly received by the clamping bolt and the tendency is to cause the clamping block 11 to wedge more tightly between t e bolt head or the washer and the side of the bit block, the strain upon the clamping bolt being very materially reduced from previous arrangements, and I have found, by actual experience, that a smaller bolt in the present arrangement will accomplish all that a larger 'bolt could accomplish in previous arrangements and the bit is more firmly held in its seat.

Having thus described the invention, I cla1m:-

1. A bit block for cutter chains compris ing a link body having a threaded opemng therein dis osed at an angle to the vertical axis of 'sai body, a bit carried by the link body, a clamping member engaging the bit and having an opening therein re 'stering with but of greater diameter t an the threaded opening, and a clamping screw extending through the opening in the clam mg member and eglgxagmg the threads of t e opening in the l' ody. 2. A bit block for cutter chains comprismg a lmk body having a flat upper face pierced by a threaded opening disdposed a o sai body, a

. an angle to the vertical axis buto bit carried by the link body, a substantially wedge-shaped member engaging the bit and having with an opemng therein registering greater diameter than the thre o emng, the walls of the opening in the c ampmg member being smooth and unobstructed, and a clampin screw extending through the openin m e clam her and eg t e threads 0 m in the a body, said screw being provi ed with an enlar ed head bearing agamstan inclined face of t e clamping member.

3. Alhblittblgaockhfor cutter d108m ris mg a y a an n a utment and provided r ii th a smooth flat face adjacent said abutment, a hol bea against the abutment a bit fitted to the h afi member :1 5% max said link body provided with a threaded opening exten mg through the flat face thereof and dismd at an angle to the vertical axis of the body; a clamping member the bitand aving its lower face flat an ening the flat face of the link body and its upper face inclined downwardl there being an opening formed in the amping t the link body aded,

member with but of ater diameter than the threaded openfn in the linkbody, a clamping screw extendin through the opening in the link body, sai clamping screw being provided with an enlarged head, and a washer interposed between the head of the clamping screw and the inface of the bit and cause the clamping memher tofrictionally en a e the link body when the cutting face 0 t e bit engages the wor c 5. A bit block for cutter chains comprising a link body, a bit carried by the link body, a clamping member mounted on the link body and engaging ing screw disposed at an acute an le to t e vertical axis of the link body an extending through the clamping member into said link b'ody whereby the impact of the cutting face of thebit with the work will be transmitted throu h the clamping member to the head of t e clamping screw. a

6. A bit block for cutter chains comprising a link body, body, a clamping w link body and engaging ing screw extendm through the wedge into and isposed at an acute angle thrust of the bit when said mounted on the to the line of bit is cutting.

In testimon whereof I afiix m signature. NEWT N K. BOWMABK ing memthe opena member gthe bit, and

the bit, and a clam a bit' carried by the link e bit, and a clamp- I 

